Seaweeds Manual

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Seaweeds A field Manual


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Seaweeds

- a field manual

National Institute of Oceanography, Dona Paula, Goa. 403 004

Disclaimer: The authors are responsible for the contents of this manual

First Edition : March 2004

V.K. DhargalkarDevanand Kavlekar

National Institute of Oceanography

Dona Paula, Goa - 403 004

Editors

X.N. Verlecar

Vijaykumar Rathod

National Institute of Oceanography,Dona Paula, Goa - 403 004

DTP

Devanand Kavlekar

Bioinformatics Centre,

National Institute of Oceanography, Dona Paula, Goa

Financial Support

Ministry of Environment & Forests, New Delhi


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FOREWORD

Since its inception in 1966 the National Institute of Oceanography is involved

in taxonomic classification of marine phytoplankton, zooplankton, benthos and

other flora and fauna under the Project Measurement and Mapping of Marine

Resources. Although the mandate of the project has been diversified with

changing times, the taxonomic identification continues to remain the thrust area

for all biological projects, especially those dealing with baseline studies on

ecobiology and environmental pollution. Visiting post-graduate and post-doctorate

students constantly look for information on taxanomic identification which is

spread over several books and journals.

The project Survey and Inventerisation of Coastal Biodiversity (West coast)

funded by Ministry of Environment and Forests (MoEF), New Delhi, provided an

opportunity to bring together taxonomic experts from various disciplines. Their

efforts have resulted in preparation of this manual. This manual provides details

of taxonomic classification and description of the concerned organisms /species.

All the figures are well illustrated and detailed identification key is provided. This

should surely guide even a beginner to understand the identification procedure.

S.R.Shetye

Director. NIO


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PREFACE

Seaweeds ! are not mere weeds but are valued marine plants. The multifacet

uses of these plants in food, chemical and textile industries, agriculture,

pharmaceuticals and medicine have been well recognized.

Our Indian coast including two groups of islands, harbour around 800

seaweed species belonging to Chlorophyta, Phaeophyta, and Rhodhophyta. This

vast and economically important ocean resource required to be conserved,

protected and utilized on sustainable bases. This is possible by following proper

scientific standerdized sampling procedure, correct species identification,

inventorization and documentation as well as quantitative assessment to evaluate

standing stock and standing crop of the economically valuable species.Often

seaweed information is scattered in books, journals, reports etc. and are not

readily available to the larger research community.

This manual presents sampling procedure, processing of the samples, wet

and dry preservations and qualitative and quantitative assessment of seaweed

resources. Keys to common genera and species are given as an examples for

the identification. For further identification upto species level books may be refered.

We are sure that this manual will be very handy and useful to the ammatuers,

students, researchers and scientists in seaweed study. We take the responsibility

of any inadvertent errors in this manual.

V.K. Dhargalkar

Devanand Kavlekar


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CONTENTS

1. Introduction

2. Green algae (Chlorophyta)

2.1 Morphology

2.2 Anatomy

2.3 Pigments

2.4 Reproduction

3. Brown algae (Phaeophyta)

3.1 Morphology

3.2 Anatomy

3.3 Pigments3.4 Reproduction

4. Red algae (Rhodophyta)

4.1 Morphology

4.2 Anatomy

4.3 Pigments

4.4 Reproduction

5. Intertidal seaweed collection procedure

5.1 Line transect or belt transect method

5.2 Random sampling method

6. Subtidal seaweed collection procedure



7. Sample preservation

7.1 Wet preservation

7.2 Dry preservation

8. Procedure for preparing herbarium

9. Identification of seaweed species

10. Quantitative assessment of abundance

11. Field data sheet

12. Labeling


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13. Key to common genera of chlorophyta

13.1 Key to species

14. Key to common genera of Phaeophyta

14.1 Key to species

15. Key to common genera of Rhodophyta

15.1 Key to species

16. References

Appendix I & II

Plates


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1. Introduction

Seaweeds or benthic marine algae are the group of plants that live either in

marine or brackish water environment. Like the land plants, seaweeds contain

photosynthetic pigments and with the help of sunlight and nutrient present in the

seawater, they photosynthesize and produce food.

Seaweeds are found in the coastal region between high tide to low tide and in the

sub-tidal region up to a depth where 0.01 % photosynthetic light is available

(Fig. 1). Plant pigments, light, exposure, depth, temperature, tides and the shore

characteristic combine to create different environment that determine the distri-

bution and variety among seaweeds.

The important criteria used

to distinguish the different

algal groups based on the

recent biochemical, physi-

ological and electron micro-

scopic studies are :

a) photosynthetic pig-

ments, b) storage food

products, c) cell wall com-

ponent, d) fine struc-

ture of the cell and e) flagella. Accordingly, algae are classified into three main

groups i.e. green (Chlorophyta), brown (Phaeophyta) and red (Rhodophyta).

Seaweeds are similar in form with the higher vascular plants but the structure and

function of the parts significantly differ from the higher plants. Seaweeds do not

have true roots, stem or leaves and whole body of the plant is called thallus that

consists of the holdfast, stipe and blade (Fig. 2).

The holdfast resembles the root of the higher

plants but its function is for attachment

and not for nutrient absorption. The hold fast

may be discoidal, rhizoidal, bulbous orbranched depending on the substratum it at-

taches. The stipe resembles the stem of the

higher plants but its main function is for sup-

port of the blade for photosynthesis and for ab

Seaweed bed

Intertidal area

Subtidal

HT

LT

Fig. 1 Beach profile showing Intertidal and Subtidal areas

Blade

Stipe

Holdfast


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sorption of nutrients from surrounding sea water. The blade may resemble

leaves of the higher plants and have variable forms (smooth, perforated,

segmented, dented, etc.). The important functions of the blade are photosyn-

thesis, absorption of nutrientThe most significant difference of seaweeds from

the higher plants is that their sex organs and sporangia are usually one celled

or if multi-cellular, their gametes and spores are not enclosed within a wall

formed by a layer of sterile or non reproductive cells.

2. Green algae (Chlorophyta)

2.1 Morphology

Green algae are found in the fresh and marine habitats. They range from unicel-

lular to multi-cellular, microscopic to macroscopic forms. Their thalli vary from

free filaments to definetely shaped forms. The photosynthetic portion of the thalli

may be moderately to highly calcified appearing in variety of forms as fan shaped

segments, feather like or star-shaped branches with teeth or pinnules and clav-

ate or globose branchlets.

2.2 Anatomy

The cell has thick and stratified cell wall consisting of an inner cellulose and

outer pectin layer. The pectin layer is impregnated with calcium carbonate in all

Dasycladales and in many Siphonales. The majority of the chlorophyceae have

uninucleate cell and multinucleate condition occurs in Cladophorales and

Siphonales during the formation of reproductive units. In some cases, cell divi-

sion occurs in plane parallel to the surface and result in a distromatic or

pleurostromatic paranchymatous thallus. Protoplast usually possesses a con-

spicuous central vacuole often traversed by cytoplasmic strands.

2.3 Pigments

Green algae possess photosynthetic pigments such as Chlorophyll a & b, con-tained in the special cell structure known as chromatophores. The chloroplast

are found in varying shapes and sizes. It has double membrane envelope and no

chloroplast endoplasmic reticulum is present. In many forms pyrenoids are present

in the chloroplast, which are the major sites of starch formation. The pyrenoids


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of green algae are variably regarded as

masses of reserve protein and as special organelles of the cell (Fig.3). Thephotosynthetic product of this group is starch.

2.4 Reproduction

Reproduction in Chlorophyceae shows great diversity. Green algae can produce

sexually and asexually by forming flagellate and sometimes non-flagellate spores.

The vegetative propagation is achieved through fragmentation.

Sexual reproduction may be by isogamous, anisogamous or oogamous type.

The simple mode of reproduction is by isogamy i.e fusion of similar gamates. In

anisogamy, both the gametes are flagellated but of different size, while in oo-gamy the male gamete is flagellated and fuses with large non-motile female

gamete to form zygote. A large num-

ber of Chlorophyceae are haploid

and reduction occurs in the germi-

nating zygote. All the oogamous

type shows similar life cycles. Ho-

mologous alternation of two identi-

cal phases is known to occur in num-

ber of Ulvalaceae and

Cladophoraceae, while all of

Siphonales appear to be deployed.

Asexual reproduction by zoospores

(motile) or aplanospores (non-motile)

produced by vegetative cells. InFig. 4 Life cycle ofUlva sp.

Fig. 3


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many cases, the cells producing zoospores are not differentiated from vegetative

cells and specialized sporangia are rare. The zoospores are formed either singly

or in some numbers from the cells. The zoospores are naked and posses a more

or less marked colourless beak at the anterior end from which flagella (two or

four) arise. Aplanospores occur in both forms normally producing zoospores and

as permanent development in many genera derived from zoosporic ancestor.

Alternation of gametophytic and sporophytic generation occurs in this group

(Fig. 4).

3. Brown algae (Phaeophyta)

3.1 Morphology

Brown algae are exclusively marine forms. They have different forms from simple,

freely branched filaments to highly

differentiated forms. Branches are

erect arising from prostrate basal

filaments held together by mucilage

forming a compact pseudo-parenchymatous aggregation of filaments into pros-

trate crust or erect branched axis or leaf like blades exhibiting the haplostrichouscondition. Many species have large massive thalli with special air bladder, vesicles

or float to make them bouyant (Fig. 5).

Fig. 5


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3.4 Reproduction

This group reproduces sexually and asexually. Several species of this group

reproduce vegetatively by fragmentation. Members of this group produce biflagel-

late neutral spores found with in one celled or many celled reproductive organs.

The asexual reproduction is by the formation of zoospores in the unilocular or

pleurilocular sporangia except in Dictyotales, Tilopteridales and Fucales. Unilocur

sporangia produce haploid gamatophytic stage, while, pleurilocular sporangia

produce diploid phase. The zoospores are asymmetric or bean shaped with two

lateral or sub apical flagella. Zoospores are formed in the single celled unilocular

sporangia by meiosis and gives rise to gametophytes.

Sexual reproduction is by isogamy, anisogamy and oogamy. In oogamous type

of reproduction, the male sex organ (antheridium) and the female sex organ

(oogamium) may be produced on the

same plant or on different plants (Fig.

6). Alternation of gametophytic and

sporophytic generations occurs in this

group except in the members of

Fucales.

4. Red algae (Rhodophyta)

4.1 Morphology

Except for few species they are exclusively marine. They vary in size and shape.

They are either epiphytes, grows as crust on the rocks or shells as a large

fleshy, branched or blade like thalli (Fig 7). The thallus is basically filamentous,

simple or branched, free or compacted to form pseudoparenchyma with uni or

multiaxial construction. They inhabit intertidal to subtidal to deeper waters.

4.3 Anatomy

Cells are eukaryotic. Inner cell wall is of cellulose and outer cell wall with amor-

phous matrix of mucopolysaccharides (i.e agar, porphyron, furcellaran,

cerrageenan) . Cells are uninucleate /multinucleate with a large centric vacuole.

The cross wall separating neighbouring cells exhibit a distinct features - the pit r

Fig. 7


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connection or pit plug. The cytoplasm exhibits a high degree of viscosity and

there is often a very firm adhesion to the wall which penetrates to the inner most

layer of the membrane. The cells of Rhodophyta are always uninucleate except

in the older cells that are multinucleate. The nuclei exhibit a prominent nucleo-

lus and a well developed network with numerous chromatin grains. The chloro-

plast varies from single, axial, stellate in primitive taxa to parietal and discoid

forms in non advance taxa.

4.3 Pigments

The colouration of Rhodophyta is due to water-soluble pigments, the red phyco-

erythrin and blue phycocyanin. Other pigments present are chlorophyll a & b,carotene etc. The photosynthetic product of this group is Floridian starch. Phy-

coerythrin pigment is found to be in the greater quantity in seaweeds of deeper

water and freely illuminated forms which also show increase ratio of phycoeryth-

rin to chlorophyll. The accessory pigments that resemble those found in

Myxophyceae are of proteins and show characteristic similar to those of globu-

lin. Red algae carry on apparently more photosynthesis in feeble light than brown

and green algae.

4.4 Reproduction

This group seldom repro-

duces asexually. All the

members of this group pro-

duce one or more kinds of

non-flagellated spores that

are either sexual or asexual

in nature.

Sexual reproduction is very

complicated involving sev-

eral structures after fusion

of gametes. The male

structure called anthe-

ridium produces a single

spermatangia which give

conchospore

bipolar sporling

conchosporangium

monospores

filament (conchocells)

germination

of carpospore

release of

carpospore

cystocarp

carposporangium

(cross section)

spermatozoa

antheridium

(cross section)

Fig. 8 Life cycle of Porphyra sp.


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5. Intertidal seaweed collection procedure

The collection of seaweeds from the intertidal area is done during the low tide. It

is necessary to go for collection one or two hours before the time of low tide as

per tide tables. This will give more time for seaweed collection and to observe

seaweeds in the natural habitat. It is important to make notes on the description

of the site location, topography, associated flora and fauna and other related

parameters. Although, there are number of methods for qualitative and quantita-

tive assessment of seaweeds, we consider here two methods which are practi-

cal and easy to study.

Material necessary for seaweed collection

Polyethylene bags

Knife or scalpel

Labeling materials (pen/pencil, labels, marker pens etc.)

Rubber bands

Field note book

Long rope (about 50 m long)

Quadrant 0.25 m 2 / 1 m2

Mono pan balance

rise to nonmotile spermatia. The female structure is a swollen carpogonium,

which usually bears a long drawn out receptive trichogyne. The zygote is

formed either by direct division as in Bangiales or after production of filamentous

outgrowth called gonimoblast which give rise to number of sporangia each form-

ing naked spore. Reduction occurs either at the first division of the zygote

nucleus or is postponed and takes place in special tetrasporangia borne on

individual distinct forms.

Some members of this group exhibit biphasic alternation of generation in which

sexual generation (gametophyte) alternates with asexual (tetrasporophyte) gen-

eration, while others are triphasic with three generation or somatic phases

(gamatophtye, caropsporophyte, tetrasporophyte) successively following one

another (Fig. 8).


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5.1 Line transect or belt

transect method

To prepare a quantitative assessment

of the marine vegetation in a given

area, a line or belt transect is laid per-

pendicular to the coast from high tide

to the low tide with the help of long

rope (Fig. 9). Sampling points along

the rope can be marked depending

on the gradient and the expanse of

the intertidal area. In case the inter-

tidal area is small, sampling points

can be marked at 5 m intervals along

the rope and if intertidal area is quite

large the sampling point can be

marked at 10 or 20 m along the rope.

A quadrant measuring 0.25 m 2 area is placed at the sampling points in

triplicate covering an area of 5 m 2 on either side of the sampling points.

Seaweed species present with in the quadrant are collected (collect com-

plete plant as far as possible along with the hold fast).

Seaweed specimen can be removed by hand but those specimen which are

closely adhering to the substrate such as crustose and mat forming seaweeds

can be removed with the help of knife or scalpel. The specimen that grow

close to the rocks can be removed with the rocks using geologists pick axe

or any other similar tools.

All the collected specimen should be counted species wise and number of

individuals in each species should be noted for quantitative assessment of

abundance, density, frequency, species richness, species diversity, percent-

age cover etc. with statistical consideration.

All the collected specimen from the quadrant should be weighed to estimate

standing crop biomass.

Collected material should be kept in the polyethylene bags/containers withproper labeling for further preservation and identification at the later stage in

the laboratory.


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Samples can be selected at random as per requirement. This can be done by

selecting sampling points in the area and using quadrant. Sampling points should

be selected in such a manner that every species of the study area has good

chance being selected. This type of sampling is usually done in the area where

the intertidal expanse is very narrow with steep gradient and also in the area

where distribution is patchy. It is also employed for qualitative estimation of the

seaweed.


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6 . Subtidal seaweed collection procedure:

For subtidal area similar methods as in the case of intertidal area i.e. random

sampling and belt/ line transact methods are used.


A transect perpendicular to coast is marked with the help of rope. The rope is

fixed with nails and marked at regular interval at 5 to 10 m depending on the

topography of the area.

The snorkeling technique is employed to sample shallow depth (0.5 to 3m) and

SCUBA diving is employed in case of deeper depth (3.0 to 30m deep). Theseaweed collection is done along the transect at 5 to 10m interval depending on

the topography of the area. A quadrant of 1.0 m2 area is used for collecting

seaweed samples at the marked points. A canoe or boat or catamaran is used

for fixing the sampling points and rope. Collected samples are analysed and

processed as mentioned above.


Samples can be selected at random from the subtidal area of 0.5 to 3 m with

snorkeling or SCUBA diving in deeper depths. A quadrant of 1 m2 area is placed

in the sampling area and seaweeds present in the quadrant are collected inpolyethylene bags and similar procedure is followed as that of intertidal sam-

pling.

7. Sample preservation

7.1 Wet preservation.

All the adhering materials such as sand particles and other debris as well

as epiphytes should be removed from the seaweeds before preservation.

A solution of 5 -10 % formaldehyde in seawater should be prepared to pre-

serve the seaweed sample.

Before adding the preservative, water from the polyethylene bags / contain-

ers should be drained and sufficient preservative should be added. Fumes of

the formaldehyde would help to fix and preserve the seaweed material. Poly-

ethylene bags should be tied with rubber bands properly to prevent leakage


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during transportation.

All the bags / containers

should be properly labeled

with date of collection, lo-

cality and time and trans-

port to the laboratory for

further identification.

7.2 Dry preservation

(herbarium)

Material required for preparing

herbarium is as follows:

Plastic trays

Forceps

Specimen mounting paper

(herbarium sheets)

Cheese cloth

Blotting paper

Herbarium wooden press

Painting brush Pencils, knife etc.

Polyetthylene bags.

8. Procedure for preparing herbarium

Fresh specimen should be cleaned of sand particles, rocks, shells, mud and

other adhering materials and epiphytes.

A tray containing fresh water (half filled) should be taken and specimen to be

mounted be placed in the water.

A herbarium sheet, size smaller than the tray to be inserted from below the

specimen and then spread the specimen on the herbarium sheet with the

help of brush in such a way that overlapping of the specimen is minimized.

After mounting the specimen on the herbarium sheet, sheet is lifted slowly

and tilted to one side to allow water to drain gradually without disturbing the


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mounted specimen.

Remove the sheet and properly arrange the specimen with the help of for-

ceps or needle if required (Fig.10).

To blot dry, herbarium sheets are placed on the newspaper sheets or blotting

paper to remove the remaining water from the herbarium.

A cheese cloth is placed on the top of the specimen in such a way that it

covers entire specimen.

Now place another sheet of the blotting paper over the herbarium sheet.

Once, all the specimen to be mounted are ready, herbaria are piled one

above the other and then placed between the two sheets of the wooden

press. The press is tied tightly with appropriate pressure by a rope.

The press is kept at room temperature for 24 hrs. After 24 hours, blotting

papersare required to be replaced. The process of replacing blotting papers

is repeated till the time specimen is free of moisture.

On drying of the specimen, the specimen get attached to the paper due to

the phycocolloid present in the seaweed.

The cheese cloth is carefully removed and herbarium sheet is properly la-

beled containing collection number, name of the specimen, locality, date of

collection and other ecological details.

Sometimes, specimen are thick and do not stick to herbarium sheets. In

such cases gum or glue may be used to stick the specimen or specimen

may be tied with thread.

Prepare three to four more sheets of each specimen. One for yourself, one

to send away for identification, one to file in museum and also for distribution

and for exchange. Sheets can be placed in the polyethylene bags and sealed

and stored.

9. Identification of seaweed speciesAlthough, identification of the seaweed species is difficult, time consuming, te-

dious; it is interesting, challanging, frustrating and humbling experience. The

identification is often not only based on simple morphological criteria but also on

reproductive structures, type of life history, cross sectional anatomical details,


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type of growth, cytology and ultrastructural criteria and increasingly molecularevidence. Beginners should get familiar, first with herbarium specimen from the

museum or reference collection before going for the field collection. Colour and

morphological differences between different genera/ species and taxonomic char-

acteristic are required to be carefully studied. Only thorough practice of handling

and distinghuishing the plants in the natural habitat will help a great deal in

learning seaweed identification.

Taxonomic identification key should be followed to identify the seaweed speci-

men. The taxonomic description of the specimen and anatomical characteristic

of the specimen to be identified should be referred from the books, monograph,

reference herbaria etc. Once you identify the specimen tentatively following thekey, you should compare it with the herbarium from reference center. Some of

the seaweed species, particularly, filamentous are difficult to identify. In such

cases chemo taxonomy or genetic approach could be employed. Later, you may

once again get it confirmed from the experts in the field.

List of the other institutes where seaweed species can be identified are as fol-

lows.

Botany Department, University of Pune, 411 007, Pune

Regional Center of CMFRI, Madapan Camp, 623 520, Tamil Nadu.

Central Salt Marine Chemical Research Institute, Bhavnagar, 364 002,

Gujarat.

Krishnamurthy Institute of Algology, 9 Lady Madhavan, 1st Cross Streets,

Mahalinga puram,Chennai 600 034.

Dept. of Botany, Andra University, Vizag, 530 003, Andhra Pradesh.

10. Quantitative assessment of abundance.

To involve more realistic picture of the structure and dynamics of seaweeds one

should resort to statistical consideration.

Density

It is the count of the number of individual of the species and the total area

sampled.


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D = n/A where D = density,

n = total number of individuals of the species

A = total area sampled.

Frequency

It is the number of samples in which species occur and total number of samples

taken.

F= j/k

where F = frequency

j = number of samples in which species occur

k = total number of samples

Cover

This is the proportion of the ground or the substratum occupied by the individuals

of the species.

C=a/A

where C = cover a = total area covered by species

A = total area sampled.

Species diversity

It is a measure of the number of species and the relative abundance of the indi-

vidual of each species.

The commonly used methods for species diversity are the Simpsons Diversity

Index and Shannon - Weiner Index

Simpsons Diversity Index

D = 1- (Pi)2

s

s

i=l

i=l


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Shannon - Weiner Index

H = -(Pi) (log2Pi)

Where D = Simpsons Diversity index

H = Shannon - Weiner Index of species Diversity

i = ith species.

Pi = Proportion of ith species calculated as :total

no. of individuals of species i/ total

no.individuals of all the species.

S = No. of species

Standing Crop Biomass

It is the weight of existing species in the given area at any one time.

B= (D) (TW/n)

where B = biomass

D = density

TW = sum of the weights of individual species in a sample.

n = number of individuals in the sample

11. Field data sheet

It is important to maintain accurate records of the field sample collection. All

information should be recorded in the field data sheet. The field data sheet must

include the date, time and locality of sample collection. Data sheet should also

include other important information pertaining to the ecological parameters. Field

notes should be recorded detailing the condition of sampling and any unusual

observations during the sampling. These notes will help great deal during the

processing of the sample and interpretation of the data.Please note, good

quality data collection and critical observations are an essential component of

the sampling programme . A sample of the field data sheet is provided in appen-

dix I.


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Plant erect, segmented ......................................................................11.11. Plant erect, calcified form flabellated segments .....................Halimeda.

Plant erect, calcareous, dichotomous branches ..................................12.

12 Plant erect, calcareous, dichotomously branched, fan or

funnel shaped flabellum ................................................Udotea

Plant multi-cellular calcified, branching in 1-3 forming whorl at

the top. .......................................................................13.

13. Plant multi-cellular, calcified, branching in 1-3

whorls at the top of axis ...........................................Acetabularia

Plant solitary, pear shaped, grass green colour ......................................14.

14. Plant solitary pear shaped with fluid filled vesicle ...........Boergesenia.Plant solitary bulb like, clavate vesicle ..................................................15.

15. Plant solitary bulb like, clavate vesicle, slightly

constricted at the base, vesicle filled with fluid ................................Valonia

Plant solitary forming small colony ......................................................16.

16. Plant solitary forming small colony, whitish

green colour with hairy tip. ........................................................Neomeris


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13.1 Key to Ulva species

1. Plants reticulate, netlike nature obscurring blade, mostlyunattached

entangled with other algae .......................... Ulva reticulata

Plants not reticulate, clearly blade like, mostly attached ................ 2

2. Plants normally divided into narrow segments; in transverse

section cells along the paler central portion of the older segments

much taller than those near the margins ....................... . Ulva fasciata

Plants simple or with broad lobes ................................................... 3

3. Blades not naturally perforate; cells in transverse

sections nearly square or taller than broad ........................ Ulva lactuca

14. Key to common Genera of Phaeophyta

1. Plant filamentous, tufted, less than 5 cm tall ............................Giffordia.Plant filamentous branched ...................................................................2.

2. Plant filamentous, uniserate branches, intercalary growth, sexual plant bears

plurilocular gametangia ...............................................Ectocarpus .

Plant filamentous, crustaceous, bears slender thread ............................3.

3 Plant filamentous, crustaceous, bears slender bifercate with ru-

diment thread ..............................................................Sphacelaria

Plant filamentous, decumbent ................................................................4.

4. Plant filamentous, decumbent below and erect above, sporangia

lateral paraphysis in sori .........................................................Ralfsia

Plant tubular, cylindrical or compressed .................................................5.5. Plant tubular, cylindrical or compressed

branching sparsely, seudodichotomous .................... Rosenvingea

Plant with expanded blade ...................................................................6.

6. Plant expanded, hollow spherical ...........................................Colpomenia


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Plant erect and spongy .........................................................................7.

7. Plant erect, net like spongy, sub-spherical

to irregular, paranchymatous...............................................Hydroclathrus .

Plant erect, branches without mid-rib.....................................................8.

8. Plant erect, dichotomously branched with rounded

apex, unilocular sporangia ................................................... Dictyota

Plant broad, sparsely branched without mid-rib....................................9.

9. Plant broad, erect, margin entire, branches

irregularly dichotomus .......................................Spatoglossum

Plant erect, dark brown, dichotomously branched .................................10.

10. Plant erect, dichotomously branched, sporangia

under surface of the blade ........................Stoechospermum

Plant erect branched with mid-rib .........................................................11.

11. Plant erect, branched with distinct mid-rib,

branching irregularly dichotomous ...................................Dictyopteris

Plant entire, lobbed ................................................................12.

12. Plant entire, lobbed,2-8 celled thick marked with

concentric row of hairs ........................................................... Padina

Plant erect, axis cylindrical bearing leaves and vesicles ......13.

13. Plant with erect axis, branched, leaves membranous,

prominent mid rib, receptacles axially ........................... Sargassum.

Plant erect, branched, receptacles not axially ......................................14.

14. Plant moderate size, main axis and branches elongated,

cylindrical or compressed, receptacles in the terminal branch .....Cystoseira

Plant erect, branched, leaves turbinate .................................................15.

15. Plant erect, leaves turbinate consists of a subterate

stalk, margin dented, receptacles in cluster ......................... Turbinaria


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15. Key to common Genera of Rhodophyta

1. Plant erect, foliaceous, margin entire, majenta colour,

stallate chloroplast with central pyrenoid ....................................Porphyra

Plant tufted, dichotomously branched .....................................2.

2. Plant tufted, dichotomous, repeatedly branched,

mucilaginous moderately calcified ..........................................Liagora

Plant erect, radially branched arising from stolonoferous portion ...............3.

3. Plant erect, 10-20 cm tall, fronds plume, cylindrical,

bare branches in lower third and densely branched

pyramidal shape above.................................................AsparogopsisPlant cartilaginous, axes erect, terate to compressed ..............................4.

4. Plant cartilaginous, terate to compress, saxicolous ......................Gelidium

Plant slender, cylindrical stolon ..............................................................5.

5. Plant cartilaginous, erect, stolon give rise to erect and

decumbent branches above and coarse short rhizoidal

branches below, axial branches are cylindrical or compressed,

stichidia are borne on the swollen tips ................................Gelidiella

Plant bushy, wiry clumps .................................................................6.

. .

6. Plant bushy, wiry clumps, lower branches some whatcreeping, upper erect tapering towards the apex ........................Gelidiopsis

Plant branched, axis cylindrical or flattened........................................7.

7. Plant branched, flattened, structurally composed of

central medulla surrounded by cortex ...............Gracilaria

Plant cylindrical, profusely branched bearing

short acute alternate branches ..........................................................8.

8. Plant erect radially branched, cylindrical, commonlybeset with numerous thorn like branchelets. Tetraspores

and cystocarps in swollen alternate branches.......................Hypnea

Plant cylindrical slightly compressed ranches...................................9.


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9. Plant cylindrical with numerous cylindrical or slightlycompressed branches, repeatedly dichotomous,

monosporangia produced on

monothecoid enlargement.........................................................Ahnfeltia

Plant more or less calcarious encrusted .......................................10.

10. Plant calcareous, epiphytic, genicula absent, hypothallum

monostromatic, secondary pit connection lacking ........Melobesia

Plant epiphytic, calcified, short apical segment ..................................11.

11. Plant calcified, epiphytic, forms fine thick pinkish

clumps,apical segment shorter.......................................................Jania

Plant calcified, calcification absent at the node.....................................12

12. Plant calcified, branches regular to irregular,

dichotomous, calcification absent at nodes ............Galaxaura

Plant calcified, intergenicula swollen.........................................13.

13. Plant calcified, except at the node, cream colour,

intergenicula slightly swollen .......................Amphiroa

Plant terate, flattened, solid or hollow ..........................................14.

14. Plant terate, flattened, laterally branched,

frequently lobbed or proliferous ..............................................Rhodymenia

Plant flattened, segmented................................................................15.

15. Plant branched, flattened, sometimes moniliform,

segmented by diaphragm ....................................................Champia

Plant flat, broadly lobbed................................................................16.

16. Plant flat, broadly lobbed, divided longitudinally into narrow

bands ...............................................................................Martensia

Plant foliaceous, irregularly branched,

membranous with mid-rib ................................................................17.

17. Plant foliaceous, irregularly branched, membranous


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withmid-rib..........................................................Caloglossa

Plant branched, loment like segments.............................................18.

18. Plant cylindrical, flattened, radially or laterally

branched, constricted into laminated segment .............Catenella

Plant form bushy clumps, erect cartilaginous....................................19.

19. Plant erect, reddish to greenish, main axis prominent,

determinate branches are arranged along the axis beset

with numerous spines.......................................................Acanthophora

Plant erect, cartilaginous, wart like determinate branchlets.................20.

20. Plant erect, cartilaginous, determinate branches

beset with wart like branchlets ...............................................Laurentia

Plant erect, cylindrical, determinate branches acute.............................21.

21. Plant erect, cylindrical, delicate in texture, determinate

branches acute, stalked antheridia, oval cystocrap ...............Chondria

Plant erect, polysiphnous axis.........................................................22.

22. Plant erect, polysiphonous axis with 5 pericental cells,

lateral branches alternate or whorled monosiphonous..............Dasya

Plant erect, axis monosiphonous...............................................23.

23. Plant erect, axis and branches at first

monosiphonous from apical cell, lateral develops into

several pericentral cells ...................................................Polysiphonia

Plant terate, filamentous, dichotomously branched..........................24.

24. Plant erect, filamentous, branched, axial filaments

corticated, nodes without spines ...........................................Ceramium

Plant erect filamentous, node with row of spines...................................25.

25. Plant erect, filamentous, node surrounded by a row of spines.....Centroceras

Plant erect, flattened to foiliaceous .................................................26.

26. Plant erect, flattened with slippery blade, branches

pinnate to irregular, texture firm, dark purple colour.................Grateloupia

Plant cylindrical, variously branched..........................................27.

27. Plant cylindrical to foliaceous, simple or variously

branched, Tetra sporangia commonly present ...........................Solieria


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16. References

Taylor, W.R. (1957). Marine algae of the Northern coast of North America, Publ.

The university of Michigan Press, Vol. I & II pp. 870

Abboti, I.A. and G.J. Hollenber (1976) Marine algae of California. Publ. Stanford

University Press. Stanford California pp. 827

Untawale, A.G., V.K. Dhargalkar and V.V. Agadi (1983) List of marine algae from

India. NIO Publ. pp 1- 46

Fritsch, F.E. (1965) The structure and reproduction of the algae Cambridge

university press Vo. I & II pp. 937

Dwson E. and Michael S. Foster (1982) Seashore plants of California. University

of California pres, Berkley Los Angeles London

Srivasan, K.S. (1969) Phycologia Indica, Icons of Indian Marinine Algae. Botani-

cal Survey of India, Calcutta. pp 52.

Oza, R.M. & S.H. Zaidi (2001) A revised checklist of Indian marine algae. CSMCRI,

Bhavnagar publication pp. 1- 296

Table: State wise seaweed species distribution along the West Coast of India.

Division Family Genera Species

Locality Gj M h G Ka Kl La Gj M h G Ka Kl La Gj Mh G Ka Kl La

Chlorophyta 12 11 5 5 4 9 25 20 7 9 7 15 61 50 13 14 23 34

Rhodophyta 20 2212 10 9 9 57 52 16 17 17 31 107 91 26 17 36 51

Phacophyta 10 7 6 6 2 4 27 17 9 10 3 12 58 44 23 18 7 21

Total 42 4023 21 15 22 109 89 32 36 27 58 226 185 72 49 66 106

Gj- Gujrat, Mh-Maharashtra, G-Goa, Ka-Karnataka, Kl- Kerala,La-Lakshadweep.


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Appendix - I

Field data sheet

Date : Time:

Location (Lat.& Long.) :

(hand drawn sketch of the locality if possible)

Tide: Cloud cover :

Atmospheric Temp. : Water Temp. :

Water samples : Water quality estimation (DO, Salinity, pH, Turbidity, Nutrients)

Details of collection

a) Open coast

i) sandy beach 1. supra littoral, 2. intertidal, 3. subtidal

ii) rocky beach

b) Estuary

i) mud flats

ii) mangroves

iii) rocky area

c) Type of transect :

d) Length of the intertidal expanse:

e) Frequency of sampling:

f) No. of quadrants at each transect :

g) No. of species recorded :

h) Dominant species :

i) % cover :

j) No. of quadrants for biomass estimation :

k) Associated fauna

i) No. of species(note the number of species separately) :

ii) Dominant species :

l) Field notes :


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NATIONAL INSTITUTE OF OCEANOGRAPHY

DONA PAULA, GOA 403 004, INDIA

serial No. 475 Date 22/10/1976

Class P h a e o p h y t a Family Scytosiphonaceae

Genus C o l p o m e n i a

Species s i n u o s a

Common Name : Oyster thief Colour

Locality R a t n a g i r i District R a t n a g i r i

State M a h a r a s h t r a Substratum

Zone Depth

Exposure Abundance

Cruise No. Station No.

Latitude Longitude

Ecological Notes

Remarks

Collected by V.V. Agadi Identified by

Appendix - II


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Chlorophyta


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Endodermis verticillata

Chlorophyta


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Chlorophyta


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Phaeophyta

Padina tetrastomatica

Padina gymnospora Stoechospermum marginatum


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Colpomenia sinuosa

Phaeophyta


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Rhodophyta


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Acanthophora specifera

Rhodophyta


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Rhodophyta

Documents

Seaweeds Manual